Energy:Energy before atmospheric entry: 6.81 x 1020 Joules = 1.63 x 105 MegaTons TNTThe average interval between impacts of this size somewhere on Earth during the last 4 billion years is 1.1 x 106years

Major Global Changes:The Earth is not strongly disturbed by the impact and loses negligible mass.The impact does not make a noticeable change in the tilt of Earth's axis (< 5 hundreths of a degree).The impact does not shift the Earth's orbit noticeably.

It would be a pretty big event -- about one in a million years. Radiation from the fireball would be lethal to a couple hundred km. Seismic shaking and ejecta reach even farther. The sound of the blast would be heard across Europe.

Quotesteeljaw354 ()

How would it impact humanity? Will humanity survive?

Absolutely. There'd be some short term climatic effects, but nothing too serious. This isn't even approaching the scale of the dinosuar-killer. A plus is that if it hits the Sahara, there's not much nearby vegetation to spread fire and smoke.

Lol, not a chance. Think of the kinetic energy of that much mass moving that quickly -- over a hundred thousand megatons of TNT! And it reaches the ground just seconds after hitting the top of atmosphere.

Actually, the Perseids, though one of the showers that never fail, have limited visibility from Norway. Even in southern Norway we only have 3 hours of reasonable darkness in mid August. The picture above was taken 23:36 local time and the sky wasn't yet properly dark.

QuoteWatsisname ()

Now the question is... do I watch from my home where there's more light pollution, but clear skies forecast, or go to the mountains where it's dark, but partly cloudy forecast?

I would go for the clear forecast, unless the light pollution is like central Tokyo.

The Perseids have been active for several weeks, so I don't think it's critical to watch during the estimated peak hour. But there definitely was more activity last night than the night before.

Quotesteeljaw354 ()

What happens when a 1km wide pure ice comet hits the earth in the Saharan desert?

It will hit the ground with nearly the same speed and mass as it had before atmospheric entry., and the local effect will be equally catastrophic whether it's Sahara or Antarctica (the crater will be different, though). It will not have time to slow down. There will be no global effects to worry about, and the radius of the catastrophic local effects will depend a lot of the impact speed.

Watsisname, yoohoo!! awesome!! dont forget there is still 1 more night to watch a peak!!in few hours if i have luck i will go outside to my balcony to lay down and maybe watch some more.at your place i guess you have to wait 14 more hours so the peak will be less for you but still will be great even if you stay to watch it from home!!

The hourly rate was about 40-50 from my [light polluted] location, but I might have missed the anticipated peak.

Quotespacer ()

dont forget there is still 1 more night to watch a peak!!

I think tonight would be better here, but I consider myself lucky to have got last night after 188 mm rain in 7 days, clearing briefly yesterday, going back to rain today. The rain has stopped now, but the fog remains, so I can't see whether there is clear sky ahead, and it's dark in two hours [followed by three hours of useful darkness].

yesterday i saw 8 meteors in 2 hours. 4 per hour...pretty low but good for polluted place with naked eye

I think you were unlucky. Many more were visible over Oslo yesterday, which is also light polluted. But even if the rate is 50 per hour, you wont see that many, not just because of light pollution, but because you're not able to watch the entire sky all the time. Most will be missed, and a lot will only be seen from the corner of your eye. Perseids are very fast and few last more than a second.